A conventional thermal printer prints predetermined printing information onto a printing medium. Such a medium is, for example, a label continuous body or a tag continuous body. The printing is done by overlapping the printing medium and an ink ribbon suspended between a ribbon winding shaft and a ribbon supply shaft and conveying the overlapped printing medium and ink ribbon in a sandwiched fashion. A printing unit including a thermal head, the ribbon winding shaft, and the ribbon supply shaft is disposed between a main body and an upper lid portion. The upper lid portion and the printing unit are supported by a support shaft to be free to rotate. Thus, by opening the upper lid portion and the printing unit, the printing medium or the ink ribbon can be replaced (see Japanese Patent Application Publication No. 2005-81729 for example).
Typically in this type of thermal printer, when the ink ribbon is replaced, or in other words when a new ink ribbon is suspended between the ribbon winding shaft and the ribbon supply shaft via the thermal head, the printing unit must be supported at a smaller angle than the upper lid portion, or in other words in a ribbon replacement state in which a working space is secured above and below the printing unit. Therefore, the upper lid portion and the printing unit must be supported by different support mechanisms.
With this conventional technique, however, the upper lid portion and the printing unit are supported by different support mechanisms, and therefore, when the upper lid portion and the printing unit are opened, the upper lid portion and the printing unit must be opened individually, leading to increased operational complexity.
Further, following replacement of the ink ribbon, the printing unit can be set in a printing position easily by exerting a closing direction force on the printing unit or the upper lid portion.
However, when the closing direction force is exerted on the printing unit during replacement of the ink ribbon, the printing unit may be closed unintentionally, and in a case where the printing unit and the upper lid portion are operated in conjunction, the upper lid portion may be closed, thereby obstructing the ink ribbon replacement operation.